fluct-, flucti-, -flux, flu-, flum-, -fluent, -fluence

(Latin: flow, flowing; moving in a continuous and smooth way; wave, moving back and forth)

fluidness
The property of flowing easily: "Adding lead makes the alloy easier to cast because the melting point is reduced and the fluidity is increased." "They believe that fluidity increases as the water gets warmer."
flume
1. A channel of steel, reinforced concrete, or wood that carries water for industrial purposes; for example, a dam.
2. To divert with a flume; such as, water in a stream, to expose the auriferous sand and gravel of the bed.
flumed
Relating to the transportation of solids by suspension or flotation in flowing water.
flush (as related to this "flow, flowing" unit)
1. To clean a toilet by making water flow through the bowl, or to undergo this process.
2. To put something into the toilet and to flush it.
3. To clean or to clear something by liberally pouring water or another liquid into, on, or through it.
4. To remove deposits of rock fragments and other debris by flushing them with a high-velocity stream of water.
5. Etymology: from Latin fluxus, "flux"; from fluere, "to flow".
flush tank
1. A temporary storage tank for water and sewage for periodic release through a sewer.
2. A small tank filled with water to flush a toilet.
flushing
The removal or reduction to a permissible level of suspended or dissolved solids or contaminants in an estuary or harbor.
flushometer
A valve that when activated releases the exact amount of water to flush a fixture.
fluvial
1. Pertaining to rivers and river activities; found or living in a river.
2. Produced by a river or stream.
fluvioglacial (adjective), more fluvioglacial, most fluvioglacial
Pertaining to streams flowing from a glacier, or to deposits laid down from glacial streams.
fluviology
1. The scientific study of rivers.
2. The facts and conditions relating to a river or a river-system.
fluviomorphology, river morphology
The study of a river channel and the network of tributaries within the river basin, in which an aerial view and the shape of a given cross section within a limited reach are examined at several points along the channel
flux concentration
The density of radiation falling on or received by a surface or body.
flux density, flux displacement
1. The amount of a given type of radiation that crosses a specified area within a specified period; such as, the number of photons passing through one square centimeter of a target in one second.
2. The electric flux passing through a surface, divided by the area of the surface.
3. A vector field that represents the differential flux of field lines per unit area.
flux factor
In metallurgy, a quality rating of silica refractories (heat-resistant materials, usually nonmetallic, which are used for furnace linings, etc.)
flux gate
A detector that produces an electric signal with magnitude and phase proportional to the magnetic field along its axis; used to demonstrate the direction of the terrestrial magnetic field.